Process of manufacturing alcohol by fermentation



Sept. 15, 1931. s. D. WELLS 1,823,014

PROCESS OF MANUFACTURING ALCOHOL BY FERMENTATION Filed May 11, 1927Cullum glewtera Jpvm on Jail TJ tube Culture 113mm 6000 C@ Cuzure12113104; ,limit iawr 50 gallon Culture on .sterilized ma@ @uw JermzerJfrllzenem yallon Z'achar @dragen Baservo aad' (25% WW/m) Carl/onl'vxz'de Conh'mww .ri' Cradle Jpirz'i No@ Wwf Fracz-OW vaforalu umllu'z'neratvr' med Fmriw Lewi@ Cem I l Soda AJM Acetate ,Baia/wb J'ydwyL /uv/ 6 y w gym Patented Sept. 15, 1931 UNITED STATES PATENT lOFFICSIDNEY D. WELLS, OF QUINCY, ILLINOIS. ASSIGNOR TO PAPER MILLLABORATORIES, INC., OF QUINCY, ILLINOIS, A CORPORATION 0F ILLINOISPROCESS OF MANUFACTURING ALCOHOL BY FERMENTATION Application led May*1l, 1927. Serial No. 190,556.

This invention relates to the production of alcohols by fermentationwhich is carried on under conditions particularly conducive to vigorousaction in a mash rich in carbohydrate and nltrogenous mattei'.

The invention is particularly directed ,to an improvement of the mashmaterial vand conditions of fermentation to ei'ect a large yield offermented product, whether it be alcohol, ketones or an aldehyde orother product obtainable by fermentation. This improvement is broughtabout by using a certain material as the basis of the bulk of the mash.ThisJ particular material is the spent cooking liquor remaining afterfibrous vegetable material has been cooked with certain particular mildcooking agents and the liquor has a neutral or only slightly acidreaction.

In cooking straw or other fibrous plant material with mild cookingagents suchas sodium carbonate, sodium sulphite, sodium sulphide and thelike or mixtures of the same for the production of paper pulp the spentcooking liquors are neutral or only slightly acid or may be readilyrendered only slightly acid and they are rich in carbohydrate andnitrogenous vegetable material. They are consequently capable ofsupporting numerous bacterial, fungus and other growths which producevarious materials such as aliphatic alcohols, acids, aldehydes, ketones,esters, carbon dioxide, hydrogen, ammonia, and others, depending on whatparticular growth or growths predominate. B using pure cultures andsterilized liquor an equipment', the number of products produced may belimited closely to the particular ones desired, and thus -results arepossible similar to those obtained from the treatment of starchymaterial in the production of grain alcohol, acetic acid, and others.

It is of the utmost importance that themateri alA of the mash used inthis present invention have the qualities,ringredients and .generalcharacteristics herein defined. A strong cooking liquor such as thatfrom caustic processes is not suitable, nor is the sugar containingmaterial resultant of the so-called sulphite cooking satisfactory forthe purposes n of the present invention.

stage. When in that stage they can withstand high temperatures whichkill all vegetative forms not capable of surviving the treatment. Mostorganisms which could contaminate the culture do not form spores and aretherefore eliminated at temperatures above 80 C. Such temperaturetreatment and elimination of undesirable forms thus constitutes shockingand the present invention is not specifically directed to these details.Test tube cultures are prepared and about six thousand cc. are preparedin glass. A fifty gallon culture is prepared on sterilized spent cookingliquor of the type used in this invention and from this quantity a onethousand gallon culture is prepared with sterilizedspent cooking liquor.Separately from the foregoing, a large amount of spent cooking liquor inbatches of approximately fifty thousand gallons is first sterilized andthen passed through coolers and then placed in the fermenting apparatusand at this stage, the above mentioned one thousand gallon culture isincorporated and the fermentingonducted in the sterilized and cooledmash thus consisting of the spent cooking, liquor. From the fermentersthe liquid containing the desired roducts is drawn off or otherwiseseparate and led to a reservoir from which it is conducted to stillsfrom which a crude spirit is obtainable. The crude spirit issubsequently fractionated and lacetone, alcohol and butanol and variousduring the fermentation and subsequent` ing cells.

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An example in the production of the solvents butanol, acetone, and ethylalcohol will be understood from the following procedure. The blackliquor obtained from washing cereal straw cooked with a solution ofsodium carbonate and sulphur is sterilized and in'- noculated with aculture of the desired microorganism and allowed to ferment at atemperature of 98 E. until the evolution of gas ceases, a period ofapproximately sixty hours. The solution is thpenl passed throughcontinuous stills which yield a crude spirit consisting of about fiftypercent mixture of butanol, acetone, and ethyl alcohol in water. Theseconstituents are separated in fractionating columns as above outlined inconnection with the accompanying drawing.

One of the important phases of this invention is the preparation of anutrient solution capable of sustaining yeast and bacteria for the.roduction of organic substances. Thus the mvention may in part ,beconsidered directed .toward the treatment of straw or other vegetablematerial for the production of the necessary nutrient solution. Inpreparing the mash, thus consisting of the )cooking liquor specificalldefined or of wash water resultant of was ing fibrous plant materialAafter such cooking, straw may be treated with a milk of lime solutioncontaining approximately ten percent of the weight of the straw CaO orit may be treated' with a solution containing live percent of its weightNaZCOa and one-half percent S, or it may be treated with a solutioncontaining seven percent NazCO. and one and one-half percent NazSOs, orit may be treated with a solution containing three percent NaOH and twopercent NazS. In each case it is cooked in a digestor at a temperatureof about 25021?. for

ten hours. IThe contents are then emptied and the water soluble matterwashed from the residue. Where milk of lime is used it is necessary toneutralize the liquors obtained Fwith II2SO4 or rNaHSO4 or some otheracid or acid salt with a divalent or tri-valent acid until tlie right hdrogen io'n concentration is obtained most avorable tothe growth ofyeast or whatever bacteria is used. In the case of cooking solutions inwhich sodiumy salts are,`

used thellquors obtained are usually approximately the right hydrogenion concentration and may bey made exactly so by means of acid oralkali. The treatment of the solution with yeast and the distillation ofthe products ob-y tained are carried lon according to the methods knownto those versed'n the art.

Where fibrous vegetable material is used, the residue obtained from thedigestion mentioned above ma be used in the manufacture of paper,paperboard or other fibrous products according to methods known to thoseversed in the art.

In a somewhat different treatment, straw may be treated with a solutioncontaining from five to ten percent of its weight in soda ash or in asolution containing from four to ten percent of its' weight of causticsoda. The other cooking conditions would be the same as above specified.Different amounts require different cooking conditions. The amount ofcooking reagent may be varied greatly and depends on the relative valueof the solvents obtainable from the spent cooking liquor and thestraw-board obtained from the fibrous residue. It has been noticed thatthe greater the amount of cooking material and the more severe thecooking conditions there results a correspondingly greater ,amount ofstraw matter dissolved in the liquor and the smaller the amount offibrous resldue.

It is important that the cooking step be alkaline or a neutral digestionand in this feature, the present process is to be differentiated fromfermentation of materials requiring the presence of sugar, as forexample, those in which wastel sulphite liquors resultant from thecooking of wood have been used and the fermentation is confined probablysolely to sugars which can exist in an aci digestion. In the presentl'mash there is probably little or no sugar. The substances which renderthe liquor of the mash of the present invention particularly importantfor fermentation purposes are peculiar in that these materials are notderived from 'cellulose but actually occur with the cellulose in theplant and are obtained without any breaking down of the celluloseto-sugar as is the condition occurringv in the bisulphite process.

'Ihe Waste liquors obtained from the mild cooking of various straws,bagasse, bamboo, grasses and the like are particularly suitable tobacterial growth. Should there be slight alkalinity, this can becounteracted by the addition of acids or acid saltsjprior to theaddition of the ferment to the mash. Suitable examples of acidifyingmaterials are sulphuric acid. phosphoric. acid, carbonic acid, sodiumacid sulphate or monocalcium phosphate or calcium superphosphate andthese materials may be used to bring about the condition of slightaci'ditv normally desirable for bacterial growth. The vegetable fibrousmaterial may be digested @primarily for the production of thesefermentable solutions and the fiber used for pape'r only as a by"product, or the cooking material may be used for themash of the presentinvention after the `usual cooking operationin the production of paper.c

The exact nature of the ingredients of the vegetable fibrous materialwhich render the cooking material o particular` importance infermentation processes is di'fiicult to determine. The materialundoubtedly includes semi-celluloses and pentosans, normally found instraw and similar vegetation, and also albuminous matter andmucilaginous substances similar to pectin. All of these ma- Y terialsdifl'er considerably from sugars, and such other carbohydratesobtainable from seyere cooking treatment of wood such as referred tohereinbefore as providing a strong acid or strong 'alkali treatment.

The conditions prescribed in the foregoing for the cooking reagent aretypical, but the present process is not limited to the particularcooking materials mentioned. Quite a wide variation of cookingmaterialsmay be used.V

However, it is of major importance that the cooking be mild and that tieaction be terminated before the vegetable material is pulped andapproximately as soon as it is sfiftened, as contrasted to being pulped.rlhus the cooking material is s ubstantially the same kind and strengthof cooking reagent as I have defined for use for the treatment ofvegetable fibrous material for the production of pulp by two stages,including first a mild cooking to effect softening as contrasted topulping and secondly, a treatment of the softened fibers by mechanicalmeans toY effect their separation and -all of which features havebeende-` finedin my Patents 1,626,171, April 26, 1927, 1 .654,624,January 3, 1928, and 1,714,459, May i, 1929. t*

The invention relating to the manufactgre of distillable spirits byfermentation is claimed in divisional application Serial No. 545,125,filed June 17, 1931.

1 claim f' 1. The process of manufacturing distillable spirits byfermentation which process comprises fermenting a mash consisting of theliquor resultant from the cooking of fibrous plant material with asolution of an alkaline carbonate and an alkaline-sulphite until thefibrous plant material is softened but not pulped, and thereby producingrecoverable distillable spirits.

2. The process of manufacturing distillable spirits by fermentationwhich process comprises preparing a mash consisting solely of the liquorresultant from the cooking ,iof fibrous plant material with asolutionof'an alkaline, carbonate and an alkalinesulphite until thefibrous plant material is softened but not pulped, adding Water`to saidliquor, slightly acidifying the mixture prior to addition of the'fermentto counteract normalu 69 alkalinity of the cooking liquor, fermentingthe mash so prepared and thereby producing recoverable 'distillablespirits.

3. The process of Ymanufacturing distillable spirits by fermentationWhich-princess t comprises fermentinga mash cogsisting of a liquorresultant from the cooking of fibrous plant material with mild cookingagents including in solution an alkaline carbonate and an alkalinesulphur compound until the fibrous plant material is softened but notpulped, and said liquor including hemicelluloses, pentosans, albuminousand mucilaginous matter, and thereby producing recoverable distillablespirits. Y

4. The process of manufacturing distillable spirits by fermentationwhichfprocess comprises fermenting a, mash consisting of the liquorresulting from Washing fibrous plant material after the same has beencooked with a. mild cooking agent comprising an alkaline carbonate andan alkaline sulphite, slightly acidifying the liquor prior. to theincorporation of the ferment, fermentingthe mash sfo prepared andthereby producing recoverable distillable spirits. i

5. The process of manufacturing distillable spirits by fermentationwhich process comprises fermenting a mash consisting solely of theliquor resultant from the cooking of fibrous plant material with a mildcook- 90 ing agent comprisinga solution of sodium sulphite and analkaline carbonate until the fibrous plant material is softened but notpulped, and thereby producing recoverable distillable spirits. A

6. The process of manufacturing chemicals by fermentation which processconsists.. of preparing a culture of a. micro-organism in an amount ofthe 'liquor'resultant fromythe cookingr of fibrous plant material with amild 10 .cooking agent including il solution sodium sulphite and anvalkaline carbonate until the fibrous plant material is`so'ftened but'notpulped, incorporating the cultui` in a large amount of the same kindof.1iqu r and per? 105 mitting fermentation to take place, and therebyproducing recoverable distillable spirits.

7. The@ process of manufacturing distill-v ble spirits by fermentationwhich process comprises fermenting a mash consisting of 11 the liquorresultantv from Vthe cooking of fibrous plant material `with a solutionof a sodium carbonagand an alkaline 'sulphur compound until the fibrousplan material-.is softened but not pulped, and hereby producingrecoverable distillable spirits.

8. The process ofA manufacturing distillable spirits by fermentationwhich process comprises fermenting'a mash consisting` of 120 the liquorresulta/nt from'the- 'cooking' of fibrous plant material with a solutionof sodium carbonate until'the fibrous plant material is softened but notpulped, and thereby producing recoverable distillable spirits.

9. The processof manufacturing distill-` able spirits by fermentationwhich process consists of fermenting amasli comprising the .liquorresultant from thecooking lof fibrous having in water mild alkalinereaction and which cooking is conducted until the fibrous plant materialis softened but not pulped, and thereby producing recoverable distllable5 spirits.

In testimony whereof yIeilx my signature.

SIDNEY D. WELLS.

